U.S. patent number 4,566,550 [Application Number 06/606,801] was granted by the patent office on 1986-01-28 for stair-climbing wheelchair carrier.
This patent grant is currently assigned to Sunwa Sharyo Manufacturing Co., Ltd.. Invention is credited to Rintaro Misawa.
United States Patent |
4,566,550 |
Misawa |
January 28, 1986 |
Stair-climbing wheelchair carrier
Abstract
A stair-climbing wheelchair carrier has a frame body, a pair of
rail frames formed in a lower portion of the frame body and a pair
of endless belt crawlers engaged with the wheels provided on the
frame body and with the rail frames. A travelling wheel mechanism
is provided on each of the rail frames at a rear portion thereof.
The travelling wheel mechanism comprises a lever rotatably mounted
on the rail frame, a pair of travelling wheels provided on both
ends of the lever, and a spring for maintaining said travelling
wheels in a position parallel with the grounding surface of the
crawlers. Both the travelling wheels are so disposed that contact
points with the ground are at lower positions than the grounding
surface of the crawlers.
Inventors: |
Misawa; Rintaro (Tokorozawa,
JP) |
Assignee: |
Sunwa Sharyo Manufacturing Co.,
Ltd. (Tokyo, JP)
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Family
ID: |
16217907 |
Appl.
No.: |
06/606,801 |
Filed: |
May 3, 1984 |
Foreign Application Priority Data
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Oct 7, 1983 [JP] |
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58-188112 |
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Current U.S.
Class: |
180/8.2; 16/18B;
180/9.22; 180/907; 280/250.1; 280/5.22; 280/DIG.10 |
Current CPC
Class: |
A61G
5/061 (20130101); A61G 5/066 (20130101); B62D
55/075 (20130101); Y10T 16/218 (20150115); Y10S
180/907 (20130101); Y10S 280/10 (20130101) |
Current International
Class: |
A61G
5/00 (20060101); A61G 5/06 (20060101); B62D
55/00 (20060101); B62D 55/075 (20060101); B62B
005/02 () |
Field of
Search: |
;180/9.22,8.2,907
;305/15,60 ;280/5.22,242WC,289WC,DIG.10 ;297/DIG.4 ;446/431
;16/18B |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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302893 |
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Nov 1932 |
|
IT |
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1546130 |
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May 1979 |
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GB |
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Primary Examiner: Peters, Jr.; Joseph F.
Assistant Examiner: Hill; Mitchell J.
Attorney, Agent or Firm: Farber; Martin A.
Claims
What is claimed is:
1. A stair-climbing wheelchair carrier comprising:
a frame body;
a pair of rail frames formed in a lower portion of said frame body,
rear ends of said rail frames having sleigh-like upward
portions;
wheels disposed on said frame body;
a handle portion provided on said frame body;
a wheelchair holding device provided on said handle portion for
holding a wheelchair;
a pair of endless belt crawlers engaged with said wheels on said
frame body and with said rail frames;
said endless belt crawlers having a predetermined span extending
two steps of a stairway and an oblique overhang portion at one end
of said frame body which has predetermined height higher than the
usual height of a step of the stairway;
a travelling wheel mechanism provided on each of said rail frames,
said travelling wheel mechanism comprising a lever rotatably
mounted on said rail frame, a pair of travelling wheels provided on
both ends of said lever, and a spring for maintaining said
travelling wheels in a position, the travelling wheels being so
disposed that contact points thereof with the ground are at lower
positions than a grounding surface of said crawlers.
2. The stair-climbing wheelchair carrier according to claim 1
wherein the line connecting centers of said travelling wheels is in
parallel with said grounding surface of said crawlers.
3. The stair-climbing wheelchair carrier according to claim 1
wherein said travelling wheel mechanism is positioned at a rear
position of said rail frame.
Description
BACKGROUND OF THE INVENTION
The present invention relates to a stair-climbing wheelchair
carrier on which a wheelchair with a disabled passenger seated
therein is mounted, and particularly to a stair-climbing wheelchair
carrier which moves smoothly on stairways as well as on flat
floors.
There is provided a stair-climbing carrier on which a wheelchair is
mounted for travelling on the stairway. For example, Japanese
Patent Laid Open Publication No. 57-95267 discloses such a
stair-climbing wheelchair carrier, in which a wheelchair is easily
mounted on the carrier which is smoothly travels on the floor.
The stair-climbing wheelchair carrier has a pair of belt crawlers
for easily descending or ascending stairs. However, the belt
crawlers increases friction between the crawlers and the floor,
which harms the operability of the carrier on the floor. In order
to solve this problem, the crawler mechanism is provided with
detachable wheels so that the carrier moves on the floor by the
wheels. However, it is quite troublesome to attach and detach the
wheels according to the travelling conditions.
SUMMARY OF THE INVENTION
The present invention is to overcome these inconveniences by the
provision of an improved stair-climbing wheelchair carrier,
providing wheel mechanisms for smooth travelling.
According to the present invention, there is provided a
stair-climbing wheelchair carrier comprising:
a frame body;
a pair of rail frames formed in a lower portion of the frame body,
wheels disposed on said frame body; a handle portion provided on
the frame body, a wheelchair holding device provided on the handle
portion for holding a wheelchair;
a pair of endless belt crawlers engaged with the wheels on the
frame body and with the rail frames; a travelling wheel mechanism
provided on each of the rail frames, the travelling wheel mechanism
comprising a lever rotatably mounted on the rail frame, a pair of
travelling wheels provided on both ends of the lever, and a spring
for maintaining the travelling wheels in a position, the travelling
wheels being so disposed that contact points with the ground are at
lower positions than the grounding surface of the crawler.
The invention will now be described with reference to the following
drawings of the preferred embodiments.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side view showing a stair-climbing wheelchair carrier
in accordance with one of the preferred embodiments of the present
invention;
FIG. 2 is a plan view of the same;
FIG. 3 is a rear view of the same;
FIG. 4 is a cross-sectional view showing the suspension of idle
wheels;
FIG. 5 is an explanatory view showing the stair-climbing operation
of the carrier;
FIG. 6 is a cross sectional view showing the attachment of
travelling wheels;
FIG. 7 is a explanatory view showing the usage of the travelling
wheels;
FIG. 8 is a perspective view showing an attaching device;
FIG. 9 is a side view showing the vicinity of the attaching
device;
FIG. 10 is a rear view of a holding handle;
FIG. 11 is a side view of the same;
FIG. 12 is a plan view showing the holding device;
FIG. 13 is a plan view of a driving pulley portion;
FIG. 14 is a plan view of a driven pulley portion;
FIG. 15 is an explanatory of the attachment of the wheelchair;
FIG. 16 shows a side view of a travelling wheel mechanism; and
FIG. 17 is a schematic view showing operation of the travelling
wheels.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
FIG. 1 is a side view generally showing a stair-climbing wheelchair
carrier 1 which is comprised of a wheelchair carrier portion 2 and
a handle portion 3.
As shown in FIGS. 1 and 2, the wheelchair carrier portion 2 has a
pair of rail-frames 4 of aluminium die-casting, rear ends of which
are curved upwards like a sleigh. These frames 4 are disposed
parallel on each side of the carrier 2.
Flanges 5 formed on ends of the frames 4 are connected to each
other through an attaching flange 8 of a reduction gear case which
combines a driving motor 6 and a reduction gear 7. Connecting
members 9 having L-shaped cross-section bridge over the frames 4 at
an intermediate position of the length of the frame 4 to constitute
the frame body of wheelchair carrier. A battery 10, a power source
of the driving motor 6, is supported on the connecting members
9.
A pair of driving wheels 12 are secured to a driving shaft 11
connected to the reduction gear 7 and idlers 14 are mounted on
shafts 15 provided on the rear or upper end of an overhang portion
13. Each idling wheel 14 is rotatably attached to each end of the
idling shaft 15 provided at the upper end of an inclined guide
portion 13. A belt crawler 17 engages with a guide groove of the
wheel 12, a grounding guide portion 16, an underface guide groove
of the overhang portion 13 and a guide groove of the idling wheel
14. A pair of the belt crawlers 17 are provided in parallel, the
distance between which is smaller than the distance between a pair
of wheels of the wheelchair.
As shown in FIG. 4, the idling shaft 15 passes through slots 19
provided in the frame 4 and a side plate 18. A holding member 20
having a U-shaped cross section is slidably provided on the frame 4
and the side plate 18. The inner end of the shaft 15 is fixed to
the holding member 20. Thus, the holding member 20 is moved along
the slots 19 together with the shaft 15 by turning a screw 21. The
screw 21 is fixed in a proper position to give a sufficient tension
to the belt crawler 17.
Considering the road and staircase condition, the belt crawlers 17
are made of elastic, synthetic rubber to absorb shock as well as to
protect the floor plate or staircase. On the outer surface of the
belt crawler 17 is provided with lugs 17a disposed at a
predetermined interval to properly engage with steps of the stair.
On the inner surface of the belt crawler 17 there are provided lugs
17b engageable with driving teeth 12a of the driving wheel 12,
preventing the belt crawler from slipping around the driving wheels
12. The belt crawler 17 has a span extending over two steps.
The grounding guide portion 16 of the rail frame 4 is bent upward
slightly at the intermediate point to form a chevron-shaped recess
16b near the center of gravity of the total load weight with the
wheelchair. Referring to FIG. 5, when the wheelchair carrier 2
starts to descend stairs, The carrier rotates gradually about the
edge E owing to the recess 16b. Therefore, the operator can put the
wheelchair carrier down on the stairs without fear.
The frame 4 has a pair of rims 4a (FIG. 6) at opposite sides of a
rear portion of the carrier for attaching travelling wheel
mechanisms 22. As shown in FIGS. 6 and 16, each travelling wheel
mechanism 22 comprises a base plate 221 secured to the rim 4aby a
pair of bolts 222 which are engaged with holes 23 and a lever 225
both ends of which are provided with travelling wheels 226a and
226b through shafts respectively. The lever 225 is rotatably
mounted on a shaft 223 through a bearing 227 at a central portion.
The shaft 223 is secured to the base plate 221. The lever 225 has a
pin 228 provided on an upper portion of the shaft 223, projecting
toward the base plate 221. A pin 224 is provided on the base plate
221 at an upper portion of the bearing 227 so as to project between
the shaft 223 and pin 228. A return spring 229 is wound on the
outer periphery of the bearing 227 in a space between the base
plate 221 and lever 225. Both ends 229a and 229b of the spring 229
are engaged with the pins 224 and 228 at the opposite sides thereof
respectively so that the lever 225 having the wheels 226a and 226b
is kept parallel to the ground surface of the crawler 17. In other
words, the line connecting centers of both wheels 226a and 226b is
positioned in parallel with the grounding surface of the crawler,
and contact points of both travelling wheels are positioned lower
than the grounding surface of the crawler.
In this embodiment, each travelling wheel has an outer diameter D
of 100 mm and a span H between the wheels is 130 mm. When wheels
226a and 226b are on a plane, a grounding surface level K of the
crawler 17 is 20 mm and an angle .theta. defined by the inclined
guide portion 13 and the plane is 45.degree.. The outer periphery
of the inclined guide portion 13 and guide portion 16 forms an arc
of circle with a radius R (see FIG. 16) at an interconnection
thereof. The center of the arc of the circle is positioned on a
vertical line L positioned displaced from the vertical center line
of the wheel 226b by Q (Q=5 mm) to have a predetermined radius of
curvature. Accordingly, the travelling wheel mechanism is adapted
to any type of steps.
Referring to FIGS. 8 and 9, an attaching device 24 is provided in a
rear portion of the wheelchair carrier 2 for attaching the handle
portion 3. The attaching device 24 comprises a pair of side plates
18, legs 26 secured to ends of the side plates 18, a shaft 27
secured to the side plates 18, idlers 25 rotatably mounted on
opposite ends of the shaft 27, and a supporting plate 28 having an
L-shaped cross section secured to the side plates 18 and a
supporting plate 30 of channel steel secured to the side plates 18
for supporting a switch box. Each leg 26 is secured to the guide
portion 16 at a lug 16a. Each idler 25 has teeth 25a which engages
with lugs 17a of the belt crawler 17, so that the upper moving
portion of the belt crawler is deflected to a substantially
horizontal plane.
A pair of engaging members 29 each of which has a rising portion
29a are secured to the upper portion of the supporting plate 28. A
hook 32 is pivotally supported on a lug 28a secured to the center
of the supporting plate 28. The hook 32 is urged in the counter
clockwise direction by a spring 33 to engage with an engaging shaft
31. The hook 32 is rotated in the clockwise direction by depressing
a pedal 32a by a person's foot.
Referring to FIGS. 10 and 11, the handle portion 3 comprises a
frame 35 having reinforcement members 34, a pair of grips 36, and a
pair of wheel holding portions 37.
An engaging device 38 is secured to the reinforcement members 34.
The engaging device 38 comprises a pair of receiving plates 39, the
engaging shaft 31 secured to the plates 39, and a pair of U-shaped
receiving members 40 secured to ends of the plates 39.
As shown in FIG. 9, the receiving members 40 engage with the shaft
27 and the engaging shaft 31 engages with the hook 32 and with the
rising portion 29a, and the plates 39 are put on the supporting
plate 28. Thus, the handle is attached to the attaching device
24.
FIG. 12 shows a wheelchair holding device 41 provided on the frame
35 of the handle 3. The wheelchair holding device 41 comprises a
pair of engaging devices 42 for engaging with a handle H of the
wheelchair, a back bar 43 for supporting the engaging devices 42,
and a pair of guide bars 44 secured to the frame 35 for supporting
the back bar 43. The back bar 43 is adapted to be moved along the
guide bars 44 and secured thereto at a desired position.
As shown in FIG. 9, an operating device is provided on a base plate
45 secured between plates 39 for operating a switch box 46 for the
motor 6. The operating device comprises a rotary shaft 47 rotatably
supported on the base plate 45, a pulley 49 secured to the shaft
47, a cable 48 engaged with the pulley 49, and an actuating plate
51 pivoted to the lower end of the shaft 47 by a pin 51a.
The actuating plate 51 engages between a pair of butterfly handles
50 which are connected by pins 50a with each other and secured to
the switch box 46. The actuating plate 51 is urged counter
clockwise by a spring 52 to engage with the pin 50a. Thus, the
rotation of actuating plate 51 may be transmitted to the handles
50. The shaft of the switch box 46 is automatically returned to the
O-position when the motor is stopped. On the other hand, a pair of
stoppers 53 are provided on the underside of the base plate 45 at a
position corresponding to the zero position. Therefore, if the
plate 51 is removed from the handles 50, the actuating plate 51 is
rotated by the spring 52, so that the other end of the plate 51
engages with the stoppers 53.
Referring to FIGS. 13 and 14, the cable 48 is wound on pulley 49
and pulley 55 provided on a support 54 about one turn respectively.
The cable 48 is slidably engaged in guide pipes 56. A pair of
handles 57 are secured to the pulley 55 positioned near grips
36.
To mount the wheelchair on the carrier 1, first the pedal 32a is
depressed by the foot to release the hook 32 from the engaging
shaft 31. Then the grips 36 of the handle portion 3 are rotated
about the shaft 27 to the raised position as shown in FIG. 15. In
such a position, wheelchair is moved on the carrier until the
wheels W abut on holding portion 37, and then the handle H of the
wheelchair is engaged with the engaging devices 42.
Thereafter, the handle portion 3 is rotated in the clockwise
direction to the initial position so that the bar 31 is engaged
with the hook 32. Thus, the wheelchair is held in position for
ascending or descending the stairs. Since the shaft 27 of the
rotation of the handle 3 is positioned near the shaft O of the
wheel W, the operation for rotating the handle 3 may be easily
accomplished with a small force. At that time, the plate 51 rotates
about the pin 51a so that the end of the plate engages between the
stoppers 53. The plate 51 engages with a pin 50a. The wheelchair
carrier 1 ascends or descends the stairs by the motor 6 by
operating the swich box 46 through the handles 57.
FIG. 17 shows the operation of the travelling wheels on steps. In
descending stairs, when the front wheel 226a touches the edge E of
the step S, the rear wheel 226b is urged to engage with the step
against the spring 229. When the rear wheel 226b engages with the
step, the lever 225 becomes horizontal, so that the wheel 226a
passes the step without turning on the edge E. At that time, the
front wheel 226a is at a higher position than the crawler 17. Then,
the lever 225 rotates in the counter-clockwise direction about the
shaft 223 by the spring 229. The rear wheel 226b also passes the
step without turning on the edge E. Travelling wheels 226a and 226b
are positioned in the spaces between the steps to remain parallel
with the crawler 17 without engaging with the steps. Thus, the lug
17a of the crawler 17 is securely engaged with the edge E. In
ascending stairs, the operation is reversed. The crawler 17 is
upwardly inclined at the inclined guide portion 13, so that the
carrier can smoothly move from stairs to a landing.
When travelling on a plane such as corridors, the handles 3 are
depressed to raise the driving wheels 12. Only travelling wheels
226a, 226b roll on the floor as shown in FIG. 7. Thus, the carrier
can be easily moved by the operator or attendant.
To remove the wheelchair from the carrier, the motor 6 is stopped
by operating the handles 57, so that the actuating plate 51 is
returned to the zero position. The wheelchair is removed in the
reverse order to the above described manner for mounting the
wheelchair.
In order to store, the wheelchair carrier 1 in a small space, the
handle portion 3 may be removed from the carrier portion 2. In such
a condition, the carrier portion 2 may be moved by directly
operating the handles 50.
* * * * *